Add initial version of erkhttp

erkhttp.go

@@ -0,0 +1,21 @@
+// Package erkhttp allows embeding HTTP statuses in erk error kinds.
+package erkhttp
+
+import "github.com/JosiahWitt/erk"
+
+// HTTPStatusable items can return an HTTP status.
+type HTTPStatusable interface {
+	HTTPStatus() int
+}
+
+// GetHTTPStatus from the kind of the provided error.
+//
+// If the status cannot be found, it defaults to 500 (Internal Server Error), and returns false.
+func GetHTTPStatus(err error) (int, bool) {
+	kind := erk.GetKind(err)
+	if statusable, ok := kind.(HTTPStatusable); ok {
+		return statusable.HTTPStatus(), true
+	}
+
+	return 500, false
+}

erkhttp_test.go

@@ -0,0 +1,63 @@
+package erkhttp_test
+
+import (
+	"errors"
+	"testing"
+
+	"github.com/JosiahWitt/erk"
+	"github.com/JosiahWitt/erkhttp"
+	"github.com/matryer/is"
+)
+
+func TestGetHTTPStatus(t *testing.T) {
+	table := []struct {
+		Name           string
+		Err            error
+		ExpectedStatus int
+		ExpectedOK     bool
+	}{
+		{
+			Name:           "with erk error with embedded status",
+			Err:            erk.New(ErkItemNotFound{}, "item not found"),
+			ExpectedStatus: 404,
+			ExpectedOK:     true,
+		},
+		{
+			Name:           "with erk error with no embedded status",
+			Err:            erk.New(ErkUnknown{}, "I don't know what happened."),
+			ExpectedStatus: 500,
+			ExpectedOK:     false,
+		},
+		{
+			Name:           "with non-erk error",
+			Err:            errors.New("not an erk error"),
+			ExpectedStatus: 500,
+			ExpectedOK:     false,
+		},
+		{
+			Name:           "with nil error",
+			Err:            nil,
+			ExpectedStatus: 500,
+			ExpectedOK:     false,
+		},
+	}
+
+	for _, entry := range table {
+		entry := entry // Pin range variable
+
+		t.Run(entry.Name, func(t *testing.T) {
+			is := is.New(t)
+
+			status, ok := erkhttp.GetHTTPStatus(entry.Err)
+			is.Equal(status, entry.ExpectedStatus)
+			is.Equal(ok, entry.ExpectedOK)
+		})
+	}
+}
+
+type ErkItemNotFound struct {
+	erk.DefaultKind
+	erkhttp.StatusNotFound
+}
+
+type ErkUnknown struct{ erk.DefaultKind }

go.mod

@@ -0,0 +1,8 @@
+module github.com/JosiahWitt/erkhttp
+
+go 1.13
+
+require (
+	github.com/JosiahWitt/erk v0.5.0
+	github.com/matryer/is v1.2.0
+)

go.sum

@@ -0,0 +1,4 @@
+github.com/JosiahWitt/erk v0.5.0 h1:2tSb5yAVLRz5SBeApE6KcQchCyxlxQFYBesqg7b7utY=
+github.com/JosiahWitt/erk v0.5.0/go.mod h1:OiLS68mTg6Aa3Olx2CHoe3Dg38Uy8MsJzHawpT8aEfQ=
+github.com/matryer/is v1.2.0 h1:92UTHpy8CDwaJ08GqLDzhhuixiBUUD1p3AU6PHddz4A=
+github.com/matryer/is v1.2.0/go.mod h1:2fLPjFQM9rhQ15aVEtbuwhJinnOqrmgXPNdZsdwlWXA=